/*
 * resp.c
 *
 * Redis Serialization Protocol
 * 
 * Copyright (C) 2024 - ntop.org
 * Copyright (C) 2024 - V.G <v.gavrilov@securitycode.ru>
 *
 * This file is part of nDPI, an open source deep packet inspection
 * library based on the OpenDPI and PACE technology by ipoque GmbH
 *
 * nDPI is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * nDPI is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with nDPI.  If not, see <http://www.gnu.org/licenses/>.
 * 
 */

#include "ndpi_protocol_ids.h"

#define NDPI_CURRENT_PROTO NDPI_PROTOCOL_RESP

#include "ndpi_api.h"
#include "ndpi_private.h"

static void ndpi_search_resp(struct ndpi_detection_module_struct *ndpi_struct,
                             struct ndpi_flow_struct *flow)
{
  struct ndpi_packet_struct const * const packet = &ndpi_struct->packet;

  NDPI_LOG_DBG(ndpi_struct, "search RESP\n");
  
  if (packet->payload_packet_len < 10)
    goto exclude;

  switch(packet->payload[0])
  {
    case '*':
    case '$':
    case '~':
      break;
    default:
      goto exclude;
  }

  u_int8_t offset = 1;
  while (offset < 4 && packet->payload[offset] != '\r')
  {
    if (!ndpi_isdigit(packet->payload[offset]))
      goto exclude;
    offset++;
  }

  if (memcmp(&packet->payload[offset], "\r\n", 2) == 0) {
    NDPI_LOG_INFO(ndpi_struct, "found RESP\n");
    ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_RESP,
                               NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI);
  }

exclude:
  NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);
}

void init_resp_dissector(struct ndpi_detection_module_struct *ndpi_struct)
{
  register_dissector("RESP", ndpi_struct,
                     ndpi_search_resp,
                     NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,
                     1, NDPI_PROTOCOL_RESP);
}
